[WhatWuzThatBlue]

Okay, so once he legally completes his time at bat he's still a batter until he leaves the box. Once he leaves the box on his way to first he's a runner. Hmmmmm

Now you've got it. He wasn't camping out, ball four had just been called and the 'batter' (i.e. the one holding the bat) chucked the bat in front of the catcher, high enough to allow it to be hit with a thrown ball. Why is it a puzzle to you? Should the batter be allowed to toss his bat five or six feet in the air, in front of a catcher who is attempting to catch a runner who is stealing third?

Yes, in your world that appears to be the case. You've said quite enough. Quoting rules, but not knowing what they mean is going to get you a good position on Officials Unlimited. Doing it on our fields will get you laughed off and never invited past tee ball again.